title: Effect of 5'-flanking sequence deletions on expression of the human insulin gene in transgenic mice.
abstract: Expression of the human insulin gene was examined in transgenic mouse lines carrying the gene with various lengths of DNA sequences 5' to the transcription start site (+1). Expression of the transgene was demonstrated by 1) the presence of human C-peptide in urine, 2) the presence of specific transcripts in pancreas, but not in other tissues, 3) the specific immunofluorescence staining of pancreatic islets for human C-peptide, and 4) the synthesis and accumulation of human (pro)insulin in isolated islets. Deletions in the injected DNA fragment of sequences upstream from positions -353, -258, and -168 allowed correct initiation of the transcripts and cell specificity of expression, while quantitative expression gradually decreased. Deletion to -58 completely abolished the expression of the gene. The amount of human product that in mice harboring the longest fragment contributes up to 50% of the total insulin does not alter the normal proportion of mice insulins I and II. These results suggest that expression of the human insulin gene in vivo results from the cooperation of several cis-regulatory elements present in the various deleted fragments. With none of the deletions used, expression of the transgene was observed in cell types other than beta-islet cells.
authors.affiliation: Institut Jacques Monod, CNRS, Université Paris VII, France.
authors.forename: M
authors.initials: M
authors.lastname: Fromont-Racine
authors.forename: D
authors.initials: D
authors.lastname: Bucchini
authors.forename: O
authors.initials: O
authors.lastname: Madsen
authors.forename: P
authors.initials: P
authors.lastname: Desbois
authors.forename: S
authors.initials: S
authors.lastname: Linde
authors.forename: J H
authors.initials: JH
authors.lastname: Nielsen
authors.forename: C
authors.initials: C
authors.lastname: Saulnier
authors.forename: M A
authors.initials: MA
authors.lastname: Ripoche
authors.forename: J
authors.initials: J
authors.lastname: Jami
authors.forename: R
authors.initials: R
authors.lastname: Pictet
mesh_terms: D000818:Animals; D002096:C-Peptide / Q000378:metabolism / Q000652:urine; D002872:Chromosome Deletion; D005260:Female; D015870:Gene Expression; D006801:Humans; D007150:Immunohistochemistry; D007328:Insulin / Q000235:genetics* / Q000378:metabolism; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D010179:Pancreas / Q000033:anatomy & histology / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics
chemical_list: D002096:C-Peptide; D007328:Insulin; D012333:RNA, Messenger